not sure if someone already mentioned this but world war three was basically stopped by one russian submariner. during the cuban missile crisis the us found a soviet sub around cuba, which then dove underwater. they dropped practice depth charges to try to force the sub to surface, but the captain thought that world war three had started. he ordered that they launch their nukes, but it needed the approval of three other high ranking guys on the crew. two of them agreed, but the third, vasili arkhipov, didn't, and argued that they should surface. he ended up convincing them, and they surfaced and had to return to russia to where they were viewed as having surrendered.